I bought an '89 LS with 170,000 miles on it -- she's blowin' more blue smoke than I counted on ('bout 1 quart of oil/300 miles). I'm 90-95% certain it needs a valve job (runs great, just pollutes way too much, esp. just after laying on the throttle after coasting).

My main question is: Assuming it's in relatively good shape, how well can I expect the bottom to hold out if I throw in a rebuilt cylinder head?

I've read that the increased compression of a rebuilt head can cause the already worn piston rings to fail. I know the original owner, and believe the car to have been driven conservatively and well maintained.

Anyone go through this?
Do I bite the bullet, and drop in a used engine?

 

Be sure you find a competent mechanic who will perform a leak down test on your engine. This will indicate where your engine, valve guides, rings, head gasket , etc is in need of repair.
good luck.

 

you should be fine installing a new head but just for reference. 95 b18b1: just broke my timing belt which folded the valves in 2 and 4 cyl's, i can get a used jdm b18b1 cheaper than i can do a rebuild, each case is different i know but i have and would do all labor including machineing of the head and still come out cheaper with used motor. i agree though easest thing to do would be compresion test, my engine had a blow by problem as well and compresion was down before belt broke, so i couldn't justify pulling the head off without doing complete rebuild which would have been 5-700.00 more than used motor with 6monthy warr. and under 50,000 miles, just fyi

 

Thank you both for your input!